I know that most of you think that Lower crankcase seals are not necassary to be repaired and have questioned the fact that I recommend them being done due to oil pressure issues...I visited a shop this week on a field tech assist and had all the service advisors and techs in a meeting. The service advisors had points like many of yours about this not being a critical repair..I advised them for a number of years of this problem can cause serious and sometimes even catastophic damage to lower and upper end of engine..so I figured I would post some information and you guys can make your own calls about your own vehicles..
with this I will show you pictures of how this works for those of you who do not know the inner workings of your N*....
Figure 1...look at the frt of this lower crankcase already removed from the engine...see the 2 large holes in frt that is where the oil pump feed and release is...
figure 2....at the top is where the pickup is that follows thru to the right into the oil pump which releases the pressure below that to lower galley to feed through the oil pump...from there back into lower crankcase freeding all 5 main bearings..
figure 3 ...notice the hole on the far left...this feeds the top end....
figure 4.... is the oil manifold notice the inpregnated gaskets...and you can see how this seals the try to keep the oil contained....now notice the outer secondary seal which keeps it leaking externally...If you begin to leak externally are you not leaking internally???thus losing oil pressure to top and bottom of engine causing saddle and bearing damage....
I dont want to scare you guys, but this is a major needed repair...I dont make money on you doing them, just trying to shed some truth..Worst case scenerio if you do not do them for a few years and they are dripping all over the place you will need lifters, cams, crankshaft ect....Minor seeping is not a problem and even a lot more, but if it is flowing back onto the trans pan they need to be done...Not right away but soon...use your judgement..
with this I will show you pictures of how this works for those of you who do not know the inner workings of your N*....
Figure 1...look at the frt of this lower crankcase already removed from the engine...see the 2 large holes in frt that is where the oil pump feed and release is...
figure 2....at the top is where the pickup is that follows thru to the right into the oil pump which releases the pressure below that to lower galley to feed through the oil pump...from there back into lower crankcase freeding all 5 main bearings..
figure 3 ...notice the hole on the far left...this feeds the top end....
figure 4.... is the oil manifold notice the inpregnated gaskets...and you can see how this seals the try to keep the oil contained....now notice the outer secondary seal which keeps it leaking externally...If you begin to leak externally are you not leaking internally???thus losing oil pressure to top and bottom of engine causing saddle and bearing damage....
I dont want to scare you guys, but this is a major needed repair...I dont make money on you doing them, just trying to shed some truth..Worst case scenerio if you do not do them for a few years and they are dripping all over the place you will need lifters, cams, crankshaft ect....Minor seeping is not a problem and even a lot more, but if it is flowing back onto the trans pan they need to be done...Not right away but soon...use your judgement..